There is apparently an expanding colony of true service trees (Sorbus domestica) in the London borough of Haringey. David Bevan writing on the Tree Trust for Haringey’s website (http://www.ttfh.org.uk/cgi-bin/web/web?Our_Walks) says “The most interesting tree in St Ann's Hospital grounds is the true service tree ... There are several mature trees - all growing close to the perimeter road. They flower in early May - and bear copious "sorbs" in October (like small red and green "apples"). They have given rise to several "self-sown" seedlings in the adjacent hedges, and the two at Railway Fields originated from here. I also remember a fine "medlar-thorn", X Crataemespilus grandiflora, which I have not seen elsewhere."
St. Ann’s Hospital is at OS grid reference TQ32398860 and the Railway Land LNR at TQ31698813.
The London Wildweb says that in a narrow strip of woodland on the southern edge of St. Ann’s Hospital grounds, alongside the embankment of the railway “There is a single wild service-tree (Sorbus torminalis), while true service-tree (Sorbus domestica) is becoming naturalised through seedlings from several planted trees”
Of particular interest is the fact that the true service trees appear to fruit well and to have been regenerating from seed, whereas the wild service (quite characteristically) has not. Clearly the true service likes the north London conditions and I think they are not common from seed in many other places.
I have, myself, grown the true service from seed taken from a fruit brought from Rome by a secretary of mine who went on holiday there. This single fruit contained three seeds and all germinated after stratification out of doors. One still flourishes in our garden in Sedlescombe and fruits intermittently, another went to the local RSPCA nature reserve in Guestling where, as far as I know, it is still growing, and the third to my secretary’s garden in Putney. I grew a further plant from seed from our garden tree and this went to the grounds of the New Vic Theatre in Stoke-on-Trent.
The medlar-hawthorn (X Crataemespilus grandiflora) is thought to be a bigeneric hybrid between the medlar (Mespilus germanica) and Midland hawthorn (Crataegus laevigata) and is occasionally found in gardens.